A network attached device (NAD) may be any type of hardware unit that is connected to a computer network. Exemplary NADs include, but are not limited to: CD-ROM drives, DVD drives, optical drives, tape drives, hard disk drives, ZIP drives, JAZ drives, routers, printers, facsimile machines, audio devices, and video devices. NADs are generally connected to a local area network (LAN) via a NAD server. A NAD server provides the users of the LAN with access to the resources of the network.
A NAD server generally refers to a node (computer) on the LAN that permits other nodes on the LAN to access one or more NADs. A NAD server processes NAD-access requests and provides the appropriate access to a NAD. The NAD server may send incoming data from the requesting node to the NAD, or may retrieve data from the NAD and send the retrieved data back to the requesting node. NAD servers are generally dedicated servers, meaning that their sole purpose is to provide access to NADs. NAD servers often support multiple network protocols, which allow them to accept NAD-access requests from various nodes in a heterogeneous network environment.
Most LANs are, or should be, protected by a bastion firewall. Bastion firewalls restrict access between an internal network, such as a LAN, and an external network, such as the Internet. Bastion firewalls are considered to be uni-directional, i.e., protecting the internal network from unauthorised traffic in-coming from the external network. Bastion firewalls are designed to run as few applications as possible in order to reduce the number of potential security risks. As such, bastion firewalls do not perform data management tasks.
Bastion firewalls are typically the only layer of security for NADs attached to a LAN. NAD servers are not equipped with a second layer of security because it is generally accepted that such a second layer of security is redundant with the bastion firewall. Therefore, once a bastion firewall is penetrated, whether by an authorized or unauthorized user, the user typically gains unrestricted access to all resources of the LAN, including any NADs. However, the level of security provided by a bastion firewall may not always supply adequate protection for the NADs of a LAN. For example, it may be desirable to establish varying levels of security clearance, such that only certain authorized users of the LAN are permitted to access a particular NAD server. Also, if a NAD server provides access to valuable or sensitive data stored on a NAD, it may be desirable to implement extra security measures to prevent an unauthorized user of the LAN, who happens to penetrate the bastion firewall, from gaining access to the NADs.
According, there remains a need for a NAD server having an integrated firewall, which provides an additional layer of security for a NAD beyond that provided by a bastion firewall.